Bisphenol polycarbonates and polyesters containing units derived from a thiodiphenol



1968 W.YJ. JACKSON, JR. AL 3,398,212

0L CA BISPHENO RBONATES AND POLY ERS CONTAINING PHENOL ITS DERIVED FROMA TH DI Filed May 2, 1

4,4'(NORBORNYLIDENE) DIPHENOL POLYESTER OR POLYCARBONATE,

INCLUDING COPOLYMERIC THIODIPHENOL, \Y OR BLEND PAPER,WOOD, METAL FOIL,PLASTIC, RUBBER, ETC.

/ s\\\ \y MOLDED OR EXTRUDED ARTICLE FIG. 2

iii (44444444444? z/v/ //2 INVENTORS WINSTON J JACKSOALJR. JOHN R.CALDWELL United States Patent 3,398,212 BISPHENOL POLYCARBONATES ANDPOLY- ESTERS CONTAINING UNITS DERIVED FROM A THIODIPHENOL Winston JeromeJackson, Jr., and John Richard Caldwell,

Kingsport, Tenn., assignors to Eastman Kodak Company, Rochester, N.Y., acorporation of New Jersey Continuation-impart of application Ser. No.292,139, July 1, 1963. This application May 2, 1967, Ser. No. 635,519

, 12 Claims. (Cl. 260860) ABSTRACT OF THE DISCLOSURE Bisphenolpolycarbonates and polyesters useful as molded objects, fibers, films,etc., are prepared from a polycyclic bisphenol [such as4,4-(2-norbornylidene)diphenol] and a thiodiphenol [such as4,4-thiodiphenol]. The thiodiphenol unit imparts improved oxidativestability to these polymers without substantially lowering the tensileor thermal properties.

This application is a continuation-impart of Caldwell and Jackson U.S.Ser. No. 292,139, filed July 1, 1963.

This invention relates to new polycarbonates and polyesters, and toshaped articles thereof. In one of its more specific aspects, thisinvention relates to copolycarbonates and copolyesters prepared frompolycyclic bisphenols and thiodiphenols, and to blends of polymerscomprising polycyclic bisphenol moieties in the polymer chain withpolymers comprising thiodiphenol moieties in the chain.

Although many bisphenol polycarbonates and polyesters have goodoxidative stability, these polymers are not sufiiciently stable for veryprolonged use in air at temperatures of 200 C. and higher. For variousreasons, the addition of conventional antioxidants has disadvantages.Phenolic and aromatic amine antioxidants tends to interact with thecarbonate and ester linkages of the polymers at elevated temperaturesand cause polymer degradation. Antioxidants also may adversely affectthe excellent electrical properties of the polymers. Many conventionalantioxidants do not have satisfactory permanence and migrate to othermaterials or environments, particularly when the polymer is heated tohigh temperatures. Often when appreciable amounts of conventionalantioxidants are added, they adversely affect the tensile strength andthermal properties of the polymers. some common antioxidants areunsuitable because of unattractive colors thereof or of degradationproducts which develop with age. Odor and toxicity are often deterrentsto the use of otherwise excellent antioxidants.

It has been proposed to utilize a thiodiphenol as a dihydroxy monomer inpolymers. However, such polymers may have poor thermal properties, suchas poor glass transition temperature. For example, 4,4'-thiodiphenolpolycarbonate has a glass transition temperature of only 113 C. Onemodification proposed has been to prepare a copolycarbonate, forexample, of the thiodiphenol and other diphenols such as bisphenol A.Bisphenol A polycarbonate has a glass transition temperature of 149 C. Acopolycarbonate of equimolar amounts of bisphenol A and4,4'-thiodiphenol has a glass transition temperature of only 125 C.Therefore, there is a need in the industry for polycarbonates andpolyesters which have improved oxidative stability and good tensile andthermal properties.

Accordingly, one of the objects of this invention is to providepolycarbonates, polyesters, and blends of such polymers containing apolycyclic bridged ring in the polymer chain, wherein the polymer orblend contains a unit derived from a thiodiphenol.

'ice

Another object of this invention is to provide such polycarbonates andpolyesters having improved oxidative stability, particularly attemperatures of 200 C. and higher.

Yet another object of this invention is to provide such polymers withoutsubstantially lowering the tensile or thermal properties.

Other objects of this invention will become apparent herein.

These and other objects are attained through the practice of thisinvention, at least one embodiment of which comprises providing a highlypolymeric linear organic polyester of (A) at least one bifunctionalcarboxylic acid selected from the group consisting of carbonic acid anddicarboxylic acids, (B) at least one polycyclic gem-bisphenol having asaturated polycyclic three-dimensional structure which includes asaturated bicyclic atomicbridged hydrocarbon ring member, and (C) atleast one thiodiphenol, said polyester having an inherent viscosity ofat least 0.4 as measured in chloroform.

:These and other objects are also attained through the practice of thisinvention, another embodiment of which comprises providing a blend of(l) .a highly polymeric linear organic polyester of (A) and (B) aboveand (2) a highly polymeric linear organic polyester of (A) and (C)above, said polyester having an inherent viscosity of at least 0.4 asmeasured in chloroform.

The generic scope of the term polyester is well known in the polymer artas encompassing both polyesters and polycarbonates, although there aresome distinguishing features in the more particular class of polyestersknown as polycarbonates. Such a definition is intended herein as will beevident from the description of this invention. In addition, the termthiodiphenol will be understood to include both unsubstituted andsubstituted thiodiphenol, examples of which are presented in thedescription of this invention.

The above-referred to polycyclic gem bisphenols may be represented bythe general formula:

HO X

RI! RI! wherein R" is a member selected from the group consisting ofhydrogen atoms, halogen atoms, and alkyl groups containing from 1 to 4carbon atoms and X is gem-bivalent radical consisting essentially of asaturated polycyclic structure which includes at least one saturatedbicyclic atomic-bridged hydrocarbon ring member.

In the drawings, FIG. 1 shows a substrate 2 coated with a layer 1 of thepolymer of this invention, both in cross-section. FIG. 2 illustrates asection of a molded or extruded article 2. The polymer of the inventionin a laminate is shown in cross-section in FIG. 3. The numerals have thesame significance in each figure.

The preferred polymers of the invention have structures in the polymerchains which may be represented by the following units:

l I R R I.

wherein each R is, independently, a member selected from the groupconsisting of H, halogen, and lower alkyl containing from 1 to about 4carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, orisobutyl, R is, for the polycarbonate, carbonyl, and for the polyester,alkoyl or, aroyl, preferably isophthaloyl, terephthaloyl, or

hexahydroterephthaloyl, and X is sulphur or is selected from the groupof radicals having the following formulas:

a oe

wherein the unit is repeated in a homopolymer or in a copolymerincluding units derived from other diphenols and/or dicarboxylic acids.Polymers having the immediately foregoing structure are disclosed insaid application Ser. No. 292,139. An example of a polyester derivedfrom the same acid and from 4,4'-thiodiphenol is:

III.

and

This may be utilized as a homopolymer, or may appear in a copolymerincluding the units of the preceding formula, in any desired amount, asdiscussed more particularly hereinafter. The proportions may also varyin the event physical blends of the two homopolymers are prepared.

A representative polycarbonate, derived from 4,4'-(2- norbornylidene)diphenol is:

which is repeated in the polymer chain. The repeating unit of apolycarbonate of 4,4-thiodiphenol has the structure:

As is pointed out elsewhere herein, position isomers of thethiodiphenols are useful, and other substituents may be present on thering. However, it is important that the thiodiphenol contains nodithio(SS-) linkages as these are unstable and cleave on oxidation. Inthe case of copolycarbonates, each of the foregoing two units appear inthe polymer chain in any proportion desired, as will be discussedfurther.

It is to be understood that polymers having each of the structuresdesignated by the Formulae II, III, IV, and V are known to the art orare novel as shown in said application Ser. No. 292,139. The inventionresides in combining polymer structures such as are shown, for example,in Formulae II and III, or in Formulae IV and V, either as copolymers orphysical blends. It will also be apparent that Formulae II, HI, IV, andV are given by way of example only, and that equivalent polymers may bederived from related polycyclic dihydroxy compounds, from relateddicarboxylic acids, and from related thiodiphenols. A portion of thestructures may be derived from other dihydroxy compounds, and in thecase of polyesters, from still other types of dicarboxylic acids. Statedbroadly, the invention comprises novel polycarbonates and otherpolyesters from certain bisphenols and the novel bisphenols. Theparticular polymers of this invention are condensed from bisphenols inwhich the bivalent connecting radical of the bisphenol contains athree-dimensional polycyclic structure containing an atomic bridge. Inall of the bisphenols which characterize the invention, the two phenolgroups are attached to a single carbon atom of the bivalent connectingradical. Bisphenols having this linkage can be called gem-bisphenols.

The linear polymers of the invention include polyesters of carbonicacid, called polycarbonates, and polyesters of dicarboxylic acids, whichcan be called dicarboxylic acid polyesters to distinguish them from thepolycarbonates.

An approximate representation which shows the threedimensional nature ofthe norbornane ring is as follows:

While the norbornane nucleus has ben emphasized above, the inventionextends to gem-bisphenols having other nuclei. There may be additionalsaturated rings in the polycyclic structure in addition to the bicyclicmember which contains the atomic bridge. These may be joined by fused orSpiro-union linkages in the polycyclic structure. Atomic bridges mayalso occur in the additional member rings of the polycyclic structure.There may be alkyl, halogen, or aromatic substituents in the connectingradical.

The atomic bridge Within the polycyclic structure may have more than onecarbon atom, e.g. (bicyclo[2.2.2]

octane There may be more than one bridge in the polycyclic structure:e.g. (tricyclo[2.2.l.O ]heptane) (adamantane) There may be alkyl, aryland halide substituents on the polycyclic structure: e.g. (substitutednorbornane) R, R and R =H, halogen, alkyl (C -C and aryl. Also, twosubstituents may be attached to the same carbon atom. Of course all ofthese substituents must be in positions which do not interfere withformation of the bisphenol. Because of steric efi'ects, certainbisphenols cannot be obtained, e.g., those from some norbornanederivatives with two alkyl or halogen substituents in the 3 or 7positions.

Additional saturated rings may be fused to the bicyclic bridged ringmember in the polycyclic structure. These may be hydrocarbon orheterocyclic rings, e.g. (hexahydro-4,7-methanoindane)(octahydro-4,7-methanoisobenzofurane) /\/l\ l J There may be additionalbridges in the fused rings, e.g.(decahydro-1,4,5,8-dimethanonaphthalene) (dodechaydro 4,9,5,8dimethano-l-cyclopenta(b)naphthalene) Additional saturated rings may bejoined in the polycyclic structure by spiro-union linkage, e.g.(spiro[cyclopropane-1,7'-norbornane] Lil Linear polycarbonates can beprepared by condensation of phosgene or a bischloroformate of a diol, ora mixture of these, with one or more diols including the novelthree-dimensional polycyclic bisphenols and/or thiodiphenols. It will beapparent that the polycarbonates formed by condensing either phosgene ordiol bischloroformates with the same or different diols, can bedescribed as consisting essentially of recurring residues of carbonicacid and the diols. By condensing the bischloroformate of one diol withanother diol, homogeneous polycarbonates having regularly recurringresidues will be obtained, whereas copolycarbonates will be obtainedhaving randomly recurring residues when a mixture of diols are condensedwith phosgene.

Linear dicarboxylic acid polyesters can be prepared by condensation ofone or more organic dicarboxylic acids, or dicarboxylic acid diesters,with one or more diols including, at least in part, one of thepolycyclic bisphenols contemplated by the present invention and/orthiodiphenols. By Whatever condensation process the polyesters areformed, they can be described as polymers consisting essentially ofcondensation residues of dicarboxylic acids and diols.

While the 4,4-diphenol compounds are preferred, as represented by theformula for the polymers given above, position isomers are included, anda more general formula is with R and R having the meaning givenheretofore. Thus, examples of thiodiphenols which are useful in theinvention are 4,4-thiodiphenol, 2,2-thiodiphenol, 4,4- thiobis 2'methylphenol, 4,4-thiobis 3-methyl phenol, 4,4-thiobis(2-chloro)phenol, and4,4-thiobis(2,6-dimethyl)phenol. The same position isomerism applies inthe case of the three-dimensional polycyclic (i.e. bridged) bisphenols,as has been suggested elsewhere herein. The 4,4-derivatives arepreferred for the reason that the polymers obtained have higher meltingpoints than do the polymers derived from other position isomers.

Gem-bisphenols useful in the invention include4,4-(2-norbornylidene)diphenols such as 4,4-(5,6-dimethyl-Z-norbornylidene) diphenol;

4,4-(2-norbornylmethylene)-diphenols such as 4,4-(3-phenyl-Z-norbornylmethylene)diphenol and 4,4-(2- norbornylmethylene -bis[2,6-dichlorophenol];

4,4 (hexahydro-4,7-methanoindan-5-ylidine)-diphenols such as4,4-(hexahydro-4,7-methanoindan-5-ylidene)- di-o-cresol;

4,4 (dodecahydro 4,9,5,8-dimethano-l-cyclopenta(b)-naphthalene-6-ylidene)diphenol;

4,4 decahydro 1,4:5,8-dimethanonaphth-Z-ylidene)diphenols such as4,4(decahydro-l,4-exo-5,8-endo-dirnethanonaphth-Z-ylidene -bis2,6-dichlorophenol]4,4-(decahydro-1,4:5,8-dimethanonaphth-Z-ylmethylene) diphenol;

4,4'- (hexahydro-4,7-methanoindan-2(or 3, or 5 )-ylmethylene) diphenols;

4,4-(hexahydro-4,7-methanoindan-l-ylidene)-diphenol;

4,4 (octahydro4,7-methanoisobenzo-furan-6-ylidene)- diphenol;

4,4-(bicyclo[3.2.1]oct-2-ylidene)diphenols such as 4,4-bicyclo[3.2.l1oct-2-ylidene)bis[2,6-dichlorophenol] 4,4-bicyclo 3 .2.2]non-2-ylidene) diphenol;

4,4-(bicyclo [2.2.2] oct-2-ylmethylene) diphenol halogen-containingderivatives thereof;

4,4 (spiro[cyclopropane-1,7'-norborn-2'-yl]methylene)- diphenols; andthe 4,4- (tricyclo- [2.2.1.0 heptan-3-ylidene) diphenols.

or the Said application Ser. No, 292,139 is referred to as teaching thepreparation of these compounds.

BISPHENOL POLYCARBONATES Polycarbonates from bisphenols may be preparedby adding phosgene and/or a bischloroformate of the thiodiphenol and/orthe gem-bisphenol to a cooled, stirred aqueous mixture containing sodiumhydroxide, the bisphenol, a catalyst, and methylene chloride phase.

The diol, if other than or in addition to the thiodiphenol and/or thegem-bisphenol, from which the bischloroformate is prepared may bearomatic, aliphatic, or alicyclic, and may be primary, secondary, ortertiary. The carbon chain of aliphatic diols may be straight, orbranched and may contain from 2 to 20 carbon atoms. Examples of diolsare ethylene glycol; 1,6-hexanediol; 1,4-hexanediol;1,4-cyclohexanedimethanol; p-Xylylenediol; 2,5-norbornanediol;trans-1,4-cyclohexanediol; 2,5- dimethyl-2,5-hexanediol; hydroquinone;and 4,4-isopropylidenediphenol. Also any of the following groups may bepresent in the molecule (R=alkyl or aryl): R C-,

CH=CH, C C, -S-, phenylene, cyclohexylene, etc.

In addition to the interfacial process for preparing the polycarbonatesof this invention, these polymers may also be prepared by addingphosgene and/or the diol bischloroformate to a stirred mixturecontaining the thiodiphenol and/or the gem-bisphenol and a tertiaryamine, such as pyridine or triethylamine. A portion of the tertiaryamine may be replaced with a solvent of the polymers, such as methylenechloride. In contrast to the interfacial process, in this process it isnot necessary to add nonaromatic diols in the form of theirbischloroformatesthe diols themselves may be added. Copolycarbonates arethen obtained when phosgene is added to the bisphenol/diol mixture inthe tertiary amine.

These polycarbonates also. may be prepared by the ester interchangeprocess, that is, by heating the thiophenol and/or the gem-bisphenol,diaryl carbonate, and a suitable catalyst under reduced pressure.Satisfactory diaryl carbonates include diphenyl carbonate, ditolylcarbonate, dixylyl carbonate, and dinitrophenyl carbonate.

The polycarbonates of this invention include copolymers.Copolycarbonates are prepared by condensing a mixture of thethiodiphenol and/ or gem-bisphenol with phosgene or the diolbischloroformate or the diaryl carbonate, or thiodiphenol with a mixtureincluding another diol bischloroformate. Block copolycarbonates areprepared by condensing a mixture of low-molecular weighthomopolycarbonates with phosgene. Mixed copolymers are prepared bycondensing the thiodiphenol and/or gem-bisphenol with a bischloroformateof a polymeric diol (e.g., polyethylene oxide bischloroformate).

Bisphenols which may be used with the bisphenols of this invention forpreparing copolycarbonates include 4,4-isopropylidenediphenol (alsoknown as bisphenol A); 4,4 isopropylidenebis[2,6-dichlorophenol];4,4-isopropylidenebis[2,6 dibromophenol]; cyclohexylidenediphenol;cyclohexylmethylenediphenol; 4,4 sulfonyldiphenol; 4,4-oxydiphenol;4,4-dihydroxydiphenol; 4,4- methylenediphenol; hydroquinone; resorcinol;l,4naph thalenediol; 2,5-naphthalenediol; and other bisphenols listed inU.S. Patent 3,030,335. Also useful are 4,4-(3- cyclohexen 1methylene)diphenol; 3,3 bis(4-hydroxyphenyl)butene;4,4'-dihydroxybenzophenone; and the like.

BISPHENOL POLYESTERS The dicarboxylic acid polyesters of this inventionare prepared by condensing the novel polycyclic bisphenols and/or thethiodiphenols with dicarboxylic acids by ester interchange reactionsbetween these bisphenols and esters of aliphatic, cycloaliphatic, andaromatic dicarboxylic acids. In place of the preferred isophthalic,terephthalic, and hexahydrophthalic acids mentioned heretofore, othersare useful. Phenyl or cresyl esters of the dicarboxylic acids areconvenient to use. Suitable aliphatic dicarboxylic acids include oxalic,dimethylmalonic, succinic, glutaric, adipic, pimelic, azelaic, sebacic,and Z-methyladipic. Suitable cycloaliphatic acids include cyclohexane-1,4-dicarboxy1ic acid, cyclohexane-1,3-dicarboxylic acid,cyclopentane-1,3-dicarboxylic acid, and 2,5-norbornanedic'arboxylicacid. Either cisor trans-forms of the acids may be used. Suitablearomatic dicarboxylic acids include 1,4-naphthalic, t-butylisophthalic,diphenic, 4,4-sulfonyldibenzoic, 4,4-oxydibenzoic, and2,5-naphthalenedicarboxylic. Other suitable acids are those found incolumn 7 of U.S. Patent 2,720,506. Mixtures containing two or moreacids, two or more bisphenols or an aliphatic or cycloaliphatic glycolwith the bisphenol may be used to give copolyesters.

Bisphenols which may be added with the polycyclic bisphenols and/or tothe thiodiphenols to give copolyesters include4,4-isopropylidenediphenol (commonly known as bisphenol A);4,4-isopropylidenebis[2,6-dichlorophenol]; 4,4 isopropylidenebis[2,6dibromophenol]; cyclohexylidenediphenol; cyclohexylmethylenediphenol;4,4-sulfonyldiphenol; 4,4-oxydiphenol; 4,4- dihydroxydiphenyl;4,4-methylenediphenol; hydroquinone; resorcinal; 1,4-naphthalenediol;2,5-naphthalenediol, and other bisphenols listed in U.S. Patent3,030,335. Block copolyesters are included.

The ester interchange between a bisphenol and the phenyl or cresyl esterof the dicarboxylic acid is catalyzed by the oxide, hydroxide, orhydride of an alkali metal or alkaline earth metal or by the free alkalior alkaline earth metal itself. Other suitable catalysts include zincoxide, lead oxide, dibutyltin oxide, sodium aluminate, butyl lithium,and phenyl lithium.

The usual method is followed of heating the reactants under vacuum toremove phenol or cresol as the condensation proceeds. It is preferred tobuild up final molecular weight by the solid-phase process in which thegranulated polymer is heated in a vacuum at a temperature somewhat belowthe melting point. It is difiicult with the polyesters of this inventionto build up molecular weight by melt polymerization due to the very highmelt viscosities inherent in the polymers.

Polycarboxylates may also be prepared from the dicarboxylic acidchlorides by heating a mixture of equivalent amounts of bisphenol andacid chloride at temperatures from 280 C. or higher, or they may bereacted in a basic solvent such as pyridine or in a Z-phase systemconsisting of aqueous alkali and organic solvent phases as described inJ. Poly. Sc. 40, 399 (1959).

Another process involves the ester interchange reaction of a monobasicaliphatic acid ester of the bisphenol with a dicarboxylic acid. Theester is heated with the acid to pro-mote ester interchange withelimination of the monobasic acid. The final stage of the polymerizationis carried out under vacuum. A catalyst such as manganese will speed thereaction.

As has been suggested above, the polymers of the invention may bemodified in a number of ways as indicated by the following table.

polycarbonate and thiodiphenol polycarbonate.

4 Blend of polyester of dicarboxylic acid and polycyclic bisphenol witha polyester of a dicarboxylic acid and a thiodiphenol.

place of part of either or both diphenols.

Other additional dicarboxylic acid in either or both cases, other diolor diphenol in place of part of either or both diphenols.

The polycarboxylic acid variants have been discussed above, as have thedihydroxy modifiers.

Of the dihydroxy constituents in the polyester or polycarbonate, in thefinal polymer whether a blend or a copolymer, the thiodiphenol comprisesat least 2 mole percent and up to 50 mole percent. The preferred amountis between about 10 mole percent and 20 mole percent. Other dihydroxyconstituents, when present, comprise up to about 50 percent of thedihydroxy constituent in the final polymer, a maximum of 25 percentbeing preferred. The three-dimensional polycyclic bisphenol comprises atleast 10 mole percent (preferably at least 50 mole percent) of thedihydroxy constituent in the final blend or copolymer, and may bepresent in amounts as high as about 98 mole percent.

Various polymers of this invention are characterized by having highheat-softening temperatures, high heatdistortion temperatures, highmoduli of elasticity, high second-order transition temperatures, andvarious other unusually valuable properties such as high degree offlexibility, improved stability, solubility in methylene chloride, highmelting points, excellent resistance to burning when chlorine is presentas a substituent, high impact strength, high Rockwell hardness, goodelectrical properties (high dielectric strength, high volumeresistivity, low dissipation factor, and constant dissipation factor anddielectric constant over a wide frequency and temperature range), etc.Not all of these properties are present in the same degree in any givenpolymer; many of these groups of polymers are clearly distinct from oneanother. However, the polymers of this invention are generallycharacterized by having a surprisingly excellent combination of highmelting range, high modulus of elasticity, high second-order transitiontemperature, and high heat-distortion temperature. As a result of thisinvention, valuable fibers, films, molding plastics and other syntheticresinous materials can be produced.

It would be expected in preparing polycarbonates and polyesters thatdecreasing the symmetry of a monomer and introducing big bulky sidegroups would diminish the higher temperature characteristics such asyielding a lower softening range. On the contrary, it has been foundthat the melting range and other properties of polycarbonates andpolyesters derived from bisphenols having polycyclic structures in theconnecting groups is increased as the size of the ring system increases.

It surprisingly appears that presence of the bulky group of thepolycyclic ring system exerts a chain stiffening efiect and also asolubilizing effect. Consequently the polymers are soluble in commonorganic solvents such as methylene chloride and chloroform, and yetstill have very high melting points, high heat distortion temperatures,high second-order transition temperatures, etc.

The inherent viscosity of the polymers should be at least as high as 0.4as measured in chloroform or other suitable solvent. For use in films,particularly for photographic film base, and for fiber applications thepolymer should have an inherent viscosity of at least 0.5 ranging upwardto about 3.0. For coatings, polymers having inherent viscosities from0.4 to 0.7 are preferred. Best results with molding or extrusioncompositions have been obtained using polymers with inherent viscositiesfrom 0.8 to 1.2.

Surprisingly, the thiodiphenol units give increased protection againstoxidation as the temperature increases. At 200 C., for instance, a2.5-mil film of 4,4-(2-norbornylidene)diphenol polycarbonate had a filmlife (became brittle on creasing) of 120 hr. in a forced-air oven at 200C. The film life of the copolymer containing units from mole percent of4,4-thiodipheno1 was over 240 hr., an improvement of 100%. At 300 C. thefilm lives were min. and 60 min., respectively, an improvement of 300%.This greatly improved resistance of the copolymer to oxidation at thehigher temperature is particularly valuable when the polymer is to beused as a hot melt adhesive.

Polymers from the halogenated bisphenols have appreciably highersecond-order transition and heat-distortion temperatures than those fromthe unhalogenated bisphenols. It is probable that the halogen atoms arefunctioning both as chain-stilfening agents and bulky side groups, thusadding to the effect of the polycyclic structure.

Since the polycyclic bisphenol polycarbonates and polyesters of thisinvention have excellent oxidative and thermal stability, they aresuitable for use in numerous applications requiring stability atelevated temperatures. Since the polymers have exceptional electricalproperties, they are particularly valuable for use as electricalinsulating materials and capacitor dielectrics when operation atelevated temperatures is essential.

Nonburning films, fibers, and plastics can be obtainedfrom thehalogenated polycyclic bisphenols. The plastics which contain no halogenare self-extinguishing without dripping.

Other applications of the invention include utility as photographic filmbase, magnetic tape base, adhesive tape base, sheet packaging materials,protective coatings, molded components for aircraft and space vehicles,and nonburning protective clothing.

The following examples will serve to more fully illustrate some of thenovel features and practices of this invention. However, it will beunderstood that these are but examples of specific embodiments of thisinvention and, therefore, not in limitation thereof. The preparativemethods are described in detail in our application Ser. No. 292,139.

In the following examples, inherent viscosities are measured inchloroform at a concentration of 0.25 g./ ml. Clear, tough films of thevarious copolymers are obtained by casting from a chlorinated solvent,such as methylene chloride, chloroform, etc. Tensile properties (tensilestrength, elongation, and modulus) are measured on an Instron tensiletester (ASTM D882-61T, Method A). The heat-distortion temperatures aremeasured in a forced-convection oven as described in ASTM D1637-61 andModern Plastics, 34 (No. 3), 169 (1956). The glass transitiontemperatures are taken as the temperatures at which the films distort0.25% at a load of 5 p.s.i. when heated in the above forced-convectionoven [Ind. Eng. Chem. Prod. Research and Develop, 2, 246 (1963)].Electrical properties are determined in accordance with ASTM D59T andD257-61. The film life is the time required for a film to become brittleenough to crack on creasing after being heated in the forced-convectionoven.

Properties of the injection-molded copolymers are determined inaccordance with ASTM D1708-59T, D747 61T, D785-51 Method A, and D256-56,Method A.

The tensile shear strengths of the copolymers, tested as hot meltadhesives, are determined on precut aluminum and steel bars (ASTMD100264). Films 2-3 mils in thickness are placed between the specimenbars, which are then clamped together with exactly 0.5-in. overlap. Theclamped specimens are then heated for 15 min. in a forced-convectionoven (polycarbonate copolymers at 350 C. and polyester copolymers at 375C.). Tensile shear strengths are determined on an Instron tensiletester. A forced-air oven is fitted around the tester for thehightemperature determinations.

Example 1 In a 3-1., three-necked flask is placed 252 g. (0.90 mole) of4,4'-(2-norbornylidene)diphenol, 21.8 g. (0.10 mole) of4,4'-thiodiphenol, 300 ml. of dry pyridine, and 1250 ml. of methylenechloride. While the solution is stirred and the temperature held at 2530C. with a cold-Water bath, phosgene is passed in at a rate of about 1-2-g./min. until 98 g. has been added. The rate is then decreased to about0.2 g./min. and addition continues until the mixture becomes veryviscous. Total phosgene added is 105.2 g. The mixture is diluted withmore methylene chloride, stirred with 200 ml. of water for 1 hr., andthen stirred with 10% hydrochloric acid to neutralize the excesspyridine. The methylene chloride layer is thoroughly washed with water,and the polymer is then precipitated by adding methanol while stirring.After being dried, the coplymer has an inherent viscosity of 0.89. Itssoftening point is above 300 C.

A clear, colorless film is obtained by casting from methylene chloride.It has the following properties: tensile strength 10,500 p.s.i., modulus3.3X10 p.s.i., elongation 16%, glass transition temperature 220 0, heat-1 1 distortion temperature 237 C., dielectric constant (at 0.1-100 kc.)2.9, dissipation factor (at 0.1-100 kc.) 0.2%, and volume resistivityohm cm.

A 2.5-mil film has a film life (defined previously) of 240 hr. at 200 C.and 60 min. at 300 C. Measured under these conditions, a 2.5-mil film ofthe homopolycarbonate containing no thiodiphenol units has a film lifeof 128 hr. at 200 C. and min. at 300 C.

The copolymer is injection-molded, and the following properties areobtained with A -in. thick tensile bars and As-in. thick fiexure bars:yield strength 11,000 p.s.i., elongation flexural modulus 2.6)(10p.s.i., Rockwell hardness L114 and M-92, and notched Izod impactstrength 1.2 ft.-lb./in. of notch. Compared to the homopolycarbonate,tensile bars of the copolymer are more resistant to oxidation andembrittlement on heating in an oven at 200 C. for 1 week. The copolymerhas good oxidative stability at 200 C. as a protective coating forshaped objects. The polymer also has good tensile shear strength onaluminum and steel, determined as described above, at 200 C.

Example 2 The purpose of this example is to show the unexpected increasein glass transition temperature (T of a polycyclicbisphenol-thiodiphenol copolycarbonate as compared to the T of abisphenol A-thiodiphenol copolycarbonate.

To illustrate further, according to Schnell, Chemistry and Physics ofPolycarbonates, Interscience Publishers (1964), p. 69, a copolycarbonateof equimolar amounts of bisphenol A and 4,4-thiodiphenol has a T of 125C. From pp. 66-67 of the Schnell reference, it is known that the T ofthe 4,4-thiodiphenol homopolycarbonate is 113 C., and that of disphenolA homopolycarbonate is 149 C. Therefore, the presence of mole percentbisphenol A in the copolycarbonate increased the T only 12 C., anincrease of 33% of the interval between the T s of the twohomopolycarbonates (113 C. and 149 C.).

When a copolycarbonate is prepared from equimolar amounts of4,4'-thiodiphenol and our 4,4'-(2-norbornylidene) diphenol, the T is 190C., which is 69% of the interval between the T s of the twohomopolycarbonates (113 C. and 224 C., the latter as shown in our US.Ser. No. 292,139). These results are summarized in the following table.

Bisphenol from which polycarbonate is prepared: T C. 4,4-thiodiphenol113 Equimolar 4,4-thiodiphenol and bisphenol A 125 Bisphenol A a- 1494,4'-thiodiphenol 113 Equimolar 4,4-thiodiphenol and4,4'-(2-norbornylidene)diphenol 190 4,4-(2-norbornylidene)diphenol 224It is very surprising that the presence of the polycyclic bisphenol inthe copolymer increased the glass transition temperature of thethiodiphenol polycarbonate so much, and it is particularly surprisingthat the percentage increase, based on the T interval of the twohomopolymers, is twice that of the bisphenol A copolymer (69% versus 33Example 3 A copolycarbonate prepared from equimolar amounts of4,4'-(2-norbornylidene)diphenol and 4,4'-thiodiphenol by the method ofExample 1 has an inherent viscosity of 1.97.

A film cast from chloroform has the following properties: tensilestrength, 10,200 p.s.i., modulus 3.2 10 p.s.i., elongation 7%, glasstransition temperature 190 C., and heat-distortion temperature 230 C. A1.0-mil film has a film life at 200 C. in excess of 300 hr. A 1.0-

mil film of the homopolycarbonate containing no thiodiphenol units has afilm life of 200 hr. at 200 C.

Example 4 The copolycarbonate of Example 3 is blended with thepolycarbonate of 4,4-(3-methyl-2-norbornylmethylene) diphenol, preparedby the procedure of Example 1, to give a blend containing an average of2 mole percent of thiodiphenol units. Blending is accomplished bydissolving the polymers in chloroform and then casting a film. Filmtensile properties and heat-distortion temperature (235 C.) of thehomopolycarbonate are unaffected by the blend. The film life of a2.0-mil film of the blend at 200 C. is greater than 100 hrs., which isthe film life of the homopolycarbonate. The blend has good tensile shearstrength on steel at 200 C.

Example 5 A copolycarbonate is prepared from mole percent of4,4-(decahydro-l,4-exo-5,8-endo-dimethanonaphth-Z- ylidene)diphenol, 20mole percent of bisphenol A, and 10 mole percent of4,4'-thiobis(2-methyl)phenol. The inherent viscosity is 0.72. A film,cast from methylene chloride, has the following properties: tensilestrength 10,800 p.s.i., modulus 3.4)(10 p.s.i., elongation 10% andheat-distortion temperature 230 C. A 1.0-mil film has a film life ofhrs. at 220 C. A 1.0-mil film of a similar polymer containing additionalbisphenol A units in place of the thiophenol units has a film life of 50hrs. at this temperature.

Example 6 A bisphenol copolyester is prepared from the following: 0.090mole of 4,4-(2-norbornylidene)diphenol, 0.010 mole of 4,4-thiodiphenol,0.050 mole of diphenyl terephthalate, 0.050 mole of diphenylisophthalate, and 0.4 mg. of lithium catalyst. To remove all of the airin the flask containing these components, the flask is evacuated andpurged with nitrogen three times. The mixture is then melted down withstirring at 200 C. A vacuum of 180 mm. is applied, and phenol isdistilled from the reaction mixture While it is heated to 225 C. during30 min. The stirred mixture is then heated to 300 C. during 1 hr., andduring this time the pressure is reduced to 20 mm. The pressure is thenfurther reduced to 0.1 mm. and heating continued at 300 C. for 30 mins.During this time the polymer attains a very high melt viscosity andwraps around the stirrer. It is cooled under vacuum, treated withacetone to aid in hardening, and ground to pass a 20-mesh screen. Thepolymer is further built up in the solid phase to a higher molecularweight by heating at 0.05 mm. while the temperature is slowly raisedduring 2 hr. from 180 C. to 300 C. This final temperature is then heldfor another hour. The polymer has an inherent viscosity of 1.17.

A film cast from chloroform has the following properties: tensilestrength 9,800 p.s.i., modulus 2.7)(10 p.s.i., elongation 21%, glasstransition temperature 240 C., heat-distortion temperature 252 C.,dielectric constant (at 0.1-100 kc.) 3.0, dissipation factor (at 0.1-100kc.) 00.2%, and volume resistivity 10 ohm-cm. The similar polyestercontaining no thiodiphenol units has essentially the same properties. A2.0-mil film has good oxidative stability and good adhesive strength at200 C.

Example 7 A copolyester is prepared from 0.080 mole of 4,4-(hexahydro-4,7-methanoindan-5-ylidene)diphenol, 0.020 mole of4,4-thiodipheno1 and 0.10 mole of diphenyl trans-1,4-cyclohexanedicarboxylate by the procedure of Example 6. The polymerhas an inherent viscosity of 0.64. A film, cast from chloroform, has thefollowing properties: tensile strength 9,400 p.s.i., modulus 2.8 X 10p.s.i., elongation 15%, and heat-distortion temperature 265 C. Thecopolymer has good tensile shear strength on steel at 200 C.

1 3 Example 8 Compared to similar polymers containing no thiodiphenolunits, the following copolymers have improved oxidative stability attemperatures of 200 C. and higher, good high temperature adhesiveproperties, excellent electrical properties, and heat-distortiontemperatures above 200 C. The polycarbonates are prepared by theprocedure of Example 1 and the polyesters by the procedure of Example 6.Satisfactory properties are obtained when the inherent viscosities areat least about 0.4 and preferably at least 0.5.

(a) Copolycarbonate from 0.9 mole 4,4-(2- norbornylmethylene)diphenoland 0.1 mole 4,4-tlnod1- phenol.

(b) Copolycarbonate from 0.7 mole 4,4'-(hexahydro-4,7-methanoindan--ylidene)diphenol and 0.3 mole 4,4- thiobis(Z-chlorophenol) (c) Copolycarbonate from 0.8 mole4,4'-(2-norbornylidene)bis(2,6-dichlorophenol) and 0.2 mole 4,4-thiobis(3-methyl)phenol.

(d) Copolyester from 0.080 mole 4,4-(5,6-dimethyl-2-n0rbornylmethylene)diphenol, 0.020 mole 4,4'-thiobis(2,6-dimethyl)phenol, and 0.10 mole diphenyl terephthalate.

(e) Copolyester from 0.070 mole 4,4-(2-norbornylidene)diphenol, 0.020mole bisphenol A, 0.010 mole 4,4- thiodiphenol, and 0.10 mole diphenylisophthalate.

(f) Blend of a homopolyester of terephthalic acid and4,4'-(2-norbornylidene)diphenol and of a homopolyester of terephthalicacid and 4,4'-thiodiphenol, each prepared according to Example 6, inamounts of 98% and 2%, respectively, by weight.

While the invention has been described with substantial emphasis uponthe use of thiodiphenols, including alkydiphenols and halodiphenolshaving up to about 18 carbon atoms, it will be apparent that other arylthiodiols may be used in addition to or in place of the thiodiphenol.Examples of such other aryl thiodiols include thiodinaphthol, etc.

Although the invention has been described in considerable detail withreference to certain preferred embodiments thereof, .it will beunderstood that variations and modifications can be effected withoutdeparting from the spirit and scope of the invention as describedhereinabove and as defined in the appended claims.

We claim:

1. A highly polymeric linear organic polyester of (A) at least onebifunctional carboxylic acid selected from the group consisting ofcarbonic acid and dicarboxylic acids, (B) at least mole percent of atleast one polycyclic gem-bisphenol having a saturated polycyclicthreedimensional structure which includes a saturated bicyclicatomic-bridged hydrocarbon ring member, and (C) from 2 up to 50 molepercent of at least one thiodiphenol, said polyester having an inherentviscosity of at least 0.4 as measured in chloroform.

2. A highly polymeric linear organic polyester as defined by claim 1wherein said polycyclic gem-bisphenol has the general formula:

RI! RI! RI] RI! wherein R" is a member selected from the groupconsisting of hydrogen atoms, halogen atoms, and alkyl groups containingfrom 1 to 4 carbon atoms and X is a gem-bivalent radical consistingessentially of a saturated polycyclic structure which includes at leastone saturated bicyclic atomic-bridged hydrocarbon ring member.

3. A highly polymeric linear organic polyester as defined by claim 2wherein said X is selected from the group of radicals having the generalformula:

wherein R is at least one member which is attached to one or more of thepolycyclic rings and is selected from the group consisting of hydrogenatoms, halogen atoms, aryl groups, and alkyl groups containing from 1 to4 carbon atoms.

4. A highly polymeric linear organic polyester as defined by claim 1wherein said polyester is a polycarbonate.

5. A highly polymeric linear organic polyester as defined by claim 1wherein said polyester is a polycarbonate of (A) carbonic acid, (B)4,4-(2-norbornylidene)diphenol, and (C) 4,4'-th:iodiphenol.

6. A highly polymeric linear organic polyester as defined by claim 1wherein said polyester is a polycarbonate of (A) carbonic acid, (B)4,4-(hexahydro-4,7-methanoindan-S-ylidene)diphenol, and (C)4,4'-thiobis(2-chlorophenol).

7. A highly polymeric linear organic polyester as defined by claim 1wherein said polyester is a polycarbonate of (A) carbonic acid, (B)4,4-(2-norbornylidene)bis(2, o-dichlorophenol), and (C)4,4'-thiobis(3-methyl) phenol.

8. A highly polymeric linear organic polyester, as defined by claim 1,of (A) terephthalic acid, (B) 4,4'-(2- norbornylidene)diphenol, and (C)4,4-thiodiphenol.

9. A highly polymeric linear organic polyester, as defined by claim 1,of (A) 1,4-cyclohexane dicarboxylic acid, (B)4,4-(hexahydro-4,7-methanoindan-S-ylidene) diphenol, and (C)4,4'-thiodiphenol.

10. A highly polymeric linear organic polyester, as defined by claim 1,of (A) diphenyl terephthalate, (B)

4,4 (5,6-dimethyl-2-norbornylmethylene)diphenol, and

(C) 4,4-thiobis(2,6-dimethyl)phenol.

11. A blend of (1) a highly polymeric linear organic polyester of (A) atleast one bifunctional carboxylic acid selected from the groupconsisting of carbonic acid and dicarboxylic acids and (B) at least 10mole percent of at least one polycyclic gem-bisphenol having a saturatedpolycyclic three-dimensional structure which includes a saturatedbicyclic atomic-bridged hydrocarbon ring member and (2) a highlypolymeric linear organic polyester of said (A) and (C) from 2 up to 50mole percent of at least one thiodiphenol, wherein the dihydroxyconstituents of said polyesters consist of from 2 up to 50 mole percentof said thiodiphenol, said polyesters having an inherent viscosity of atleast 0.4 as measured in chloroform.

12. A blend as defined by claim 11 wherein (1) is a polyester of (A)terephthalic acid and (B) 4,4'-(2-norbornylidene)diphenol and (2) is apolyester of (A) terephthalic acid and (B) 4,4'-thiodiphenol.

No references cited.

MURRAY TILLMAN, Primary Examiner. J. T. GOOLKASIAN, Assistant Examiner.

